Probing the quantum phase transition around $N\approx 60$ via mass measurements of technetium isotopes

Abstract

The masses of neutron-rich ${}^{104-106}$Tc isotopes were measured using the JYFLTRAP double Penning trap and found to deviate from the Atomic Mass Evaluation 2020 by $-79(25)$, $40(12)$ and $94(41)$ keV, respectively. In the case of ${}^{105,106}$Tc, the updated $Q_{\hat{I}}^2$ values are in agreement with a previous JYFLTRAP measurement, disagreeing with the values from the mass evaluation. The new mass values result in a more linear trend in two-neutron separation energies indicating that technetium ($Z=43$) isotopes around $N\approx 60$ are not a part of the island of shape coexistence around ${}^{100}$Zr${}_{60}$.

8 pages, 4 figures